Factor the following expression: $36x^2 - 49$
The expression is of the form ${a^2} - {b^2}$ , which is a difference of two squares so we can factor it as $({a} + {b}) ({a} - {b})$ What are the values of $a$ and $b$ $ a = \sqrt{36x^2} = 6x$ $ b = \sqrt{49} = 7$ Use the values we found for $a$ and $b$ to complete the factored expression, $({a} + {b}) ({a} - {b})$ So we can factor the expression as: $({6x} + {7}) ({6x} - {7})$